The Basal Lamina of the Neuromuscular Junction
- J.R. Sanes and
- A.Y. Chiu
This extract was created in the absence of an abstract.
Excerpt
Each muscle fiber in skeletal muscle is ensheathed by a layer of extracellular matrix material, the basal lamina (BL). BL extends between nerve and muscle at the neuromuscular junction and projects into folds that invaginate the postsynaptic membrane (Fig. la). BL thus comprises a large fraction of the synaptic cleft material of the neuromuscular junction, and it presents this material in a form that is highly structured, morphologically identifiable, and susceptible to experimental analysis. In contrast, extracellular material in the clefts of interneuronal synapses has been particularly difficult to study.
Denervated adult muscle is readily reinnervated, and it has been known for nearly a century that regenerating axons preferentially form new synapses at original synaptic sites on the muscle fiber surface (Ramon y Cajal 1928; Gutmann and Young 1944; Bennett and Pettigrew 1976; Letinsky et al. 1976). In frog muscle, for example, axons regenerating after nerve crush make more than...
